FIG. 16 shows such a head slider 14, which comprises a flat slider body 2 of ferromagnetic oxide, and a winding portion 3 including yokes 36, 36 made of ferromagnetic oxide and joined to one end of the body with glass. The slider is provided, on the surface thereof to be opposed to recording media, with air bearing portions 5, 5 extending in the direction of movement of the medium in parallel to each other and having a predetermined height. The junction of the body and the yoke is formed with a track portion 6 including a gap spacer 64 and with a winding groove 4.
With the magnetic head slider described, the winding yoke 36 has a width t which is approximately equal to the width w of the air bearing portion 5. Since the width w of the air bearing 5 is about 400 .mu.m, the width t of the yoke, i.e., the width of the ferromagnetic portion forming the yoke, is excessively large to increase the inductance of the magnetic head.
To give improved high-frequency characteristics to ensure a higher recording density, it is required to minimize the inductance, whereas the conventional shape of the yoke fails to meet this requirement.
Sliders have been proposed in which the width t of the yoke 36 is smaller than the width w of the air bearings 5, 5 (U.S. Pat. No. 5,012,572).
Nevertheless, when the width t of the yoke 36 is to be made smaller than the width w of the air bearing 5, the width t of the yoke is limited to about 200 .mu.m if smallest in view of the strength of the yoke 36. Widths smaller than this limit lead to impaired strength, which poses the problem that a break or crack is liable to develop in the yoke and the junction of the yoke and the slider body during production to result in a markedly reduced yield.
The magnetic head slider 14 is prepared by heating the slider body 2 and the winding yoke 36 as butted against each other under pressure and melting glass to join the yoke to the body. This step involves the problems that the glass 33 flows into the winding groove 4 to narrow the opening thereof, consequently presenting difficulty in winding a conductor on the head slider 14 as completed.